Could I possibly have a baby cooking in my tummy?

Okay so on the 4th of July, my boyfriend and I had intercourse. Im not on any kind of birth control and he wasnt wearing a condom this time..He ended up finishing inside of me. Then three days later, the last day that I could, I took the day-after pill. Today is July 12th and again I have started a light period. Could I be pregnant?